Stephen Cole Kleene

Infobox_Scientist
name = Stephen Kleene


caption =
birth_date = birth date|1909|1|5
birth_place = USA
death_date = death date and age|1994|1|25|1909|1|5
death_place =
residence = USA
nationality = USA
field = Mathematics
work_institutions = University of Wisconsin-Madison
alma_mater = Princeton University
doctoral_advisor = Alonzo Church
doctoral_students = John Addison Jr.
Paul Axt
Douglas Clarke
Robert Constable
David Kierstead
Shih-Chao Liu
Joan Moschovakis
Yiannis Moschovakis
Nels Nelson
Gene Rose
Clifford Spector
Richard Vesley
Dick de Jongh
known_for =
prizes =
religion =
footnotes =

Stephen Cole Kleene (January 5, 1909, Hartford, Connecticut, USA – January 25, 1994, Madison, Wisconsin) was an American mathematician who helped lay the foundations for theoretical computer science. One of many distinguished students of Alonzo Church, Kleene, along with Alan Turing, Emil Post, and others, is best known as a founder of the branch of mathematical logic known as recursion theory. Kleene's work grounds the study of which functions are computable. A number of mathematical concepts are named after him: Kleene hierarchy, Kleene algebra, the Kleene star, Kleene's recursion theorem and the Kleene fixpoint theorem. He also invented regular expressions, and was a leading American advocate of mathematical intuitionism.

Kleene pronounced his last name IPAEng|ˈkleɪni. IPA|/ˈkliːni/ and IPA|/ˈkliːn/ are common mispronunciations.

Biography

Kleene was awarded the BA degree from Amherst College in 1930. He was awarded the Ph.D. in mathematics from Princeton University in 1934. His thesis, entitled "A Theory of Positive Integers in Formal Logic", was supervised by Alonzo Church. In the 1930s, he did important work on Church's lambda calculus. In 1935, he joined the mathematics department at the University of Wisconsin-Madison, where he spent nearly all of his career. After two years as an instructor, he was appointed assistant professor in 1937.

While a visiting scholar at the Institute for Advanced Study in Princeton, 1939-40, he laid the foundation for recursion theory, an area that would be his lifelong research interest. In 1941, he returned to Amherst College in 1941, where he spent one year as an associate professor of mathematics.

During World War II, Kleene was a lieutenant commander in the United States Navy. He was an instructor of navigation at the U.S. Naval Reserve's Midshipmen's School in New York, and then a project director at the Naval Research Laboratory in Washington, D.C.

In 1946, Kleene returned to Wisconsin, becoming a full professor in 1948 and the Cyrus C. MacDuffee professor of mathematics in 1964. He was chair of the Department of Mathematics and Computer Science, 1962-63, and Dean of the College of Letters and Science from 1969 to 1974. The latter appointment he took on despite the considerable student unrest of the day, stemming from the Vietnam War. He retired from the University of Wisconsin in 1979. The mathematics library at the University of Wisconsin was renamed in his honour.

Kleene's teaching at Wisconsin resulted in three texts in mathematical logic, Kleene (1952, 1967) and Kleene and Vesley (1965), often cited and still in print. Kleene (1952) wrote alternative proofs to the Gödel's incompleteness theorems that enhanced their canonical status and made them easier to teach and understand. Kleene and Vesley (1965) is the classic American introduction to intuitionist logic and mathematics. Kleene's standing among logicians is suggested by the witticism "Kleeneliness is next to Gödeliness", a pun on "Cleanliness is next to godliness".Fact|date=April 2007

Kleene served as president of the Association of Symbolic Logic, 1956-58, and of the International Union of the History and the Philosophy of Science, 1961. In 1990, he was awarded the National Medal of Science.

Kleene and his spouse Nancy Elliott had four children. He had a lifelong devotion to the family farm in Maine. An avid mountain climber and canoeist, he had a strong interest in nature and the environment and was active in many conservation causes.

Important publications

*1952. " [http://worldcat.org/oclc/523942 Introduction to Metamathematics.] " North-Holland (originally published by D. Van Nostrand).
*1956. "Representation of Events in Nerve Nets and Finite Automata" in [http://worldcat.org/oclc/564148 Automata Studies] ". Claude Shannon and John McCarthy, eds.
*1965 (with Richard Eugene Vesley). "The Foundations of Intuitionistic Mathematics". North-Holland.
*1967. " [http://worldcat.org/oclc/523472 Mathematical Logic.] " John Wiley. Dover reprint, 2001. ISBN 0486425339.
*1981. "Origins of Recursive Function Theory" in " [http://worldcat.org/oclc/4583089 Annals of the History of Computing 3,] " No. 1.

See also

* Kleene closure (or Kleene star)
* Kleene hierarchy
* Kleene's s-m-n Theorem
* Realizability
* Intuitionism
* Kleene-Rosser paradox

References

*

External links

*
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* [http://www.nap.edu/html/biomems/skleene.html Biographical memoir] – by Saunders Mac Lane
* [http://math.library.wisc.edu/bibliography.html Kleene bibliography.]
* [http://infoshare1.princeton.edu/libraries/firestone/rbsc/finding_aids/mathoral/pmc23.htm Interview] with Kleene and John Barkley Rosser about their experiences at Princeton